Studying And Analyzing the modulators and demodulators of PCM

Modulating signals of transmission stations to reception stations is a key factor to guarantee the best possible transmission and reception of these signals .Digital modulation represents a huge evolution in communication field and modulation, which used to depend on analog signal modulation of one parameter-Amplitude . frequency or phase. Digital modulation depends on transforming the transmitted data signal (Bits) and then sending it as samples, and changed back into an analog signals in reception station . In digital systems, digital data are transformed into analog data in the transmitter and does the reverse in the receiver. In digital transmission, on the other hand, as in wired local area networks (WLAN), Digital data are transmitted in their digital state.

Development electrical drive Vector control system for three phase induction motor Crane Wire, according to the principle indirect rotor field orientation

In this paper, the development of the drive system of the motor Wire port Crane according to the principle of the indirect field orientation. Require the operation of the port Crane operations, different operation situations of variable speed and Torque with time, which is a case dynamic electro and electro-magnetic transient, may affect the performance of operations, so therefore been building motor Wire port Crane operations system corps in winches achieve: - High performance and Efficiency. - Build the desired control system according to the principle of the Pulse Width Modulation (PWM) and the main power system, taking into account the reduction of changes DC-Link voltage and achieve maximum flux before starting the motor. - Reduction of excess Voltage that may appear on a DC-Link, using the brake Transistor with Brake resisters. At the end of the research has been reviewed and the search results that indicate the outstanding performance of the proposed system with the ability to use the same system to run automated processes different.